Chapter 638: City Construction (9)

"This is a dark crystal that the Devil clan had buried underground when they constructed the city, and it is only available in their world. It contains many dark elements, and when positioned here, it can activate the array in this room. The walls of the whole city would be reinforced, and no current siege weapons would be able to damage it even if they were to attack it continuously for ten years."

"It's that powerful?" Shen Yanxiao's eyes nearly popped out of their socket. The Devil clan was wise indeed.

"However, there were already cracks on the existing walls. Did someone bombard the city for hundreds of years?"

"Those marks were caused by the God race's besieging weapons."